I can confirm that it is an issue with lag. If you get a lag spike, things disappear or change (For example, mini map will be wiped clean, heroes will sometimes vanish completely (Can't see even health bar), sometimes they will sink under the ground,you can get the model bug where they appear as their base models.

You get some pretty interesting ones too where it portrays friendly creeps as enemy creeps and vice-versa. It's funny to see a dire creep leading a column of radiant creeps like he is running like hell.